Wouldn't Rubens be better in pastel colours?

At Iori, an auction hosue in Modena, they sell a painting as "School of Rubens", 60 by 78 cm. At first glance, it has nothing to do with Rubens, but this time they are actually right as it is a reverse copy of a Rubens composition, "The Triuph of the Church". However, reverse copies are usually after engravings, which means that not only many details and the typical Rubens style are lost, but the copiist also has to invent the colours. In this case, they are quite un-Rubens-like. Estimated at a rather excessive (and wide) 10,000 to 20,000 Euro! But fun to see and discuss, even though it's way too expensive for a not so brilliant copy.

The original above can be seen in the Prado.